What are the physical symptoms of the disease?

The symptom of Duchenne Muscular Dystrophy is mainly muscle weakness. Muscle weakness leads to frequent falling, clumsiness, hard to get up, and bad motor skills (jogging, sitting, jumping). Also, fatigue and mental retardation is commmon. Most people affected with it end up in a wheelchair by 12 years old due to weakness in legs and pelvis. Even though it's not as severe as the legs and pelvis, arms, neck, and other body parts are affected. All symptoms should be noticeable before the age of 6 years old and younger.